Wide-field Infrared Survey Explorer science payload update

Abstract

The Wide Field Infrared Survey Explorer is a NASA Medium Class Explorer mission to perform a high-sensitivity, high resolution, all-sky survey in four infrared wavelength bands. The science payload is a 40 cm aperture cryogenically cooled infrared telescope with four 1024 2 infrared focal plane arrays covering from 2.8 to 26 µm. Mercury cadmium telluride (MCT) detectors are used for the 3.3 µm and 4.6 µm channels, and Si:As detectors are used for the 12 µm and 23 µm wavelength channels. A cryogenic scan mirror freezes the field of view on the sky over the 9.9-second frame integration time. A two-stage solid hydrogen cryostat provides cooling to temperatures less than 17 K and 8.3 K at the telescope and Si:As focal planes, respectively. The science payload collects continuous data on orbit for the seven-month baseline mission with a goal to support a year-long mission, if possible. As of the writing of this paper, the payload subassemblies are complete, and the payload has begun integration and test. This paper provides a payload overview and discusses instrument status and performance.

Distributions of debris as measured by the NASA-WISE instrument

“…al. [1] are converted from spectral radiance to power received by integrating over the spectral bandwidth and then multiplying the radiant emittance by the area of the instrument aperture. The results shown in Table 4, for the sensitivity, in terms of the lower bound on received power, demonstrate order of magnitude agreement between the pre-light laboratory measured estimate and the estimate based on the debris population analysis presented in this paper.…”

“…The instrument spectral bands are (3.4, 4.6, 12, and 22 m). More details of the instrument, including pre-launch instrument sensitivity are documented in Reference [1] and references therein.…”

Wide-field Infrared Survey Explorer cryogenic support system lessons learned

“…This paper will present a brief overview of the cryogenic support system (CSS) followed by a discussion of the lessons learned during the development of the project and the most recent status of the cryostat. More detailed descriptions of the WISE instrument and the CSS design have been published previously [1], [2], [3] .…”

The Wide-field Infrared Survey Explorer (WISE) beamsplitter assembly

“…The Wide Field Infrared Survey Explorer (WISE) mission 1,2 and the WISE payload 3 has been described in recent papers. This paper describes the WISE Beamsplitter Assembly (BSA) that splits optical output from the WISE telescope into 4 spectral bands and contains the 4 WISE focal plane assemblies (FPA).…”